WESTFIELD — Dozens of state employees at Barnes and Otis Air National Guard hope to be compensated for benefits they say they lost while being incorrectly classified as civilians.

Raul C. Santos, a security officer and union representative, said guards, engineers, maintenance workers and other employees at the two bases were made state employees in 2010 following unrelated state and federal audits of the Massachusetts National Guard.

The audit revealed that civilians working at Barnes and Otis should be classified as state workers, not private-sector employees, Santos said.

“We should have been public employees and should have received the benefits of public employees,” said Santos, steward for Local 888 of the Service Employees Union, which represents about 30 security officers at Barnes and Otis.

“We just want what we were entitled to all along,” he added.

A spokesman for the Massachusetts National Guard said the guards are negotiating a contract and would not comment on their claims. “We don’t want to negotiate in public,” said Major Lisa M. Ahaesy, public affairs officer.

A union steward at Barnes, William Matthieson, declined to comment.

Santos said the current and former employees at Barnes and Otis will consider a class action lawsuit suit to recover lost wages and benefits.

Santos estimated the several hundred former civilian employees were never able to contribute to pension plans, leaving them with nothing when they retired.

“We’re not going to sue them for $100 million, but they were responsible for this,” he added.

Civilian employees at both bases are paid with federal funds. Currently, Barnes has about 50 civilian workers, including 15 security officers; the total number of civilians at Otis was not available Friday.